Currently, there are many kinds of computer mouse available on the market, which are the most popular human-machine interface used by computers as cursor-control device. There are three basic types of mice, which are mechanical mouse, LED optical mouse and laser mouse with respect to the different means of detection. A typical mechanical mouse comprises a chassis containing a ball, with a part of the ball protruding through the underside of the chassis. When a user moves the mouse about on a flat surface, the ball rotates which is detected by the sensors arranged in the chassis. Unfortunately the moving parts of such a mouse can become dirty, causing the sensors to incorrectly measure ball rotation. A typical LED optical mouse has a small, red light-emitting diode (LED) that bounces light off that surface with sufficient roughness onto a complimentary metal-oxide semiconductor (CMOS) sensor. The CMOS sensor sends each image to a digital signal processor (DSP) for analysis, that the DSP is able to detect patterns of shadows generated by the roughness of the surface in the images and see how those patterns have moved since the previous image. Based on the change in patterns over a sequence of images, the DSP determines how far the mouse has moved and sends the corresponding coordinates to the computer. However, if the working surface of the LED optical mouse is a smooth surface made of marble, tile, or metal, etc., such mouse might not be able to operate without a hitch. A laser mouse is an advanced optical mouse, which is capable of emitting a coherent light so as to detect more surface pattern variation than the standard LED based optical mice. Nevertheless, such laser mice are not able to operate fluently while working on a transparent surface made of glass, acrylic, and so on.
Since most conventional computer mice are disadvantageous as stated above, it is popular to have an inertial sensing module embedded inside a pointing device for using the inertial sensing module to detect and measure movements of the pointing device operating while sitting on a flat surface or being held in a free space. One such research is a pointing device disclosed in U.S. Pat. No. 5,825,350, entitled “Electronic Pointing Apparatus and Method”. The foregoing pointing apparatus is capable of controlling cursor movement and selecting elements on a computer screen no matter it is being held to move on a surface or in a free space by selectively enabling the pointing device to operate in a mode of two-dimensional detection or in a mode of three-dimensional detection, in which two gyroscopic elements are provided for indicating yaw and pitch movements of the pointing apparatus in free space, and a mouse ball and relating mouse ball encoders are provided for indicating movement of the pointing apparatus on a surface.
In recent years, more and more consumer electronic products have gyroscopic elements embedded therein as motion sensors. One such application is a free space pointing device disclosed in U.S. Pub. No. 2005/0253806, entitled “Free Space Pointing Devices and Methods”. The aforesaid space pointing device, configured with a first rotational sensor, a second rotational sensor, and an accelerometer, is capable of using a micro processing unit to modify the first and second rotational outputs based on the acceleration, respectively detected by the first rotational sensor, the second rotational sensor and an accelerometer, so as to generate an output based on said modified first and second rotational outputs.
However, those pointing devices disclosed in prior arts are designed simply to communicate with corresponding computation apparatuses, but they fall short of acting as an interface control device to interact with multimedia gaming programs. Therefore, an interactive pointing device integrating a conventional pointing device and interactive game control interface is needed for facilitating users to control computation apparatuses and interact with multimedia gaming programs.